REPORT ON THE RADIOLARIA. 1251 



V 



4. Sethamphora mongolfieri, Haeckel. 



Eucyrtidium mongolfieri, Ehrenberg, 1854, Mikrogeol., Taf. xxxiv. fig. 18; Abhandl. d. k. 

 Akad. d. Wiss. Berlin, 1875, p. 72, Taf. x. fig. 3. 



Shell urceolate, smooth, with distinct collar stricture. Length of the two joints = 2:9, breadth 

 = 3:7. Cephalis campanulate, with eighteen ribs and small pores. Thorax nearly ellipsoidal, with 

 eighteen prominent ribs, and eighteen longitudinal rows of regular circular pores between them 

 (eight pores in each row ; therefore 144 pores altogether). Mouth constricted, only one-third as broad 

 as the thorax. 



Dimensions. Cephalis 0'02 long, 0'03 broad; thorax 0'09 long, 0'07 broad. 



Habitat. Fossil in Barbados. 



5. Sethamphora costata, n. sp. 



Shell urceolate, smooth, very similar to the preceding species ; also with eighteen longitudinal 

 ribs, but differing in the larger size of the cephalis and its pores, and in the more slender and ovate 

 form of the thorax. Length of the two joints = 5 : 10, breadth = 5 : 8. Pores of the cephalis more 

 numerous. Mouth half as broad as the thorax. 



Dimensions. Cephalis 0'05 long, 0'05 broad ; thorax O'l long, 0'08 broad. 



Habitat. Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 



6. Sethamphora serrata, n. sp. 



Shell ovate, spinulate, without external collar stricture. Length of the two joints = l:6, 

 breadth = 2:4. Cephalis flat, cap-shaped, with small circular pores. Thorax ovate, truncate, 

 with eighteen serrate longitudinal ribs, alternating with eighteen longitudinal rows of short and 

 broad rather oblong pores (twenty to thirty pores in each row). Mouth strongly constricted, only 

 one-fourth as broad as the thorax. 



Dimensions. Cephalis 0'02 long, - 04 broad ; thorax 012 long, 0'08 broad, 



Habitat. Tropical Atlantic, Station 348, depth 2450 fathoms. 



7. Sethamphora ampulla, Haeckel. 



Eucyrtidium ampulla, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 15; Abhandl. d. k. Akad. 

 d. Wiss. Berlin, 1875, p. 72, Taf. x. figs. 11, 12. 



Shell broad, urceolate, spiny, with sharp collar stricture. Length of the two joints = 1:4, 

 breadth = 1 : 5. Cephalis subspherical, with few small pores (in figs. 12. and 12J of Ehrenberg, loc. cit., 

 broken off, so that the four pores of the cortinar septum appear). Thorax inflated, bottle-shaped, with 

 twenty prominent, sharply dentate ribs, alternating with twenty longitudinal rows of circular pores 

 (about eight pores in each row). Mouth flat, constricted, one-third as broad as the thorax. 



Dimensions. Cephalis 0'025 long, Q'03 broad ; thorax O'l long, 0'14 broad. 



Habitat. Fossil in Barbados. 



